In divorce cases, attorneys will often call upon a business valuation expert to distinguish between “active” and “passive” appreciation when deciding how certain spousal assets should be divided and allocated. The difference is crucial. A spouse’s interest in a closely-held business often represents the most valuable asset he or she owns and is also often the most complex to value for dissolution purposes, particularly if the spouse owned the business interest prior to marriage. In most states (including Florida), the active appreciation of a pre-marital asset is includible in the marital estate while passive appreciation is not. This means that the appreciation in value of the owner-spouse’s active involvement in the business during the marriage is included as a marital asset subject to equitable distribution. On the other hand, if a pre-marital asset increases in value during the marriage due to external market conditions (passive appreciation), it is excluded from the marital estate and remains the sole property of the owner-spouse.